Hard Questions about Treating SMA

As I reported in this blog last December, the FDA has approved a new treatment for Spinal Muscular Atrophy or SMA. This is the genetic neuromuscular disease which I have. My particular variety would be considered Type 2. I never walked as an infant but the disease has progressed quite slowly and as I’m approaching my 63rd birthday I’m still alive. The most severe Type 1 makes infants so weak that their life expectancy without extreme measures is a year or two. Some children are living as much as three or four years using trachs, ventilators, and other extensive medical support systems.

The new drug which was approved was only tested on the most severe Type 1 individuals but has been approved for Type 2 and Type 3 as well. The drug is administered by a spinal injection and is extremely expensive costing up to $500,000 the first year and perhaps $300,000 each year thereafter. The disease is caused by a failure to create a necessary protein called the SMN protein. The lack of this protein causes a deterioration in motor neuron cells called anterior horn cells. One of the big questions I’ve had about the new drug is that if these motor neuron cells have completely deteriorated, it would seem to me the most is that any drug therapy could possibly accomplish is to maintain current health levels and not actually reverse the disease. Yet the initial clinical trials of these Type 1 patients have showed not just stabilization but actual improvement.

The big question is what about older patients. I’m not just talking someone in their 60s like myself but let’s suppose you are in your 20s. If you been living with the disease not long, one would expect that these motor neurons would be completely gone. This treatment is not going to regenerate those neurons. Could you really expect any actual improvement or are we just talking stabilization. Also given that the drug is administered by spinal injection and adult patients either have severe scoliosis like I do or they’ve had spinal fusion surgery (which I probably should have had years ago). Either of which make administering the drug more difficult.

It’s one thing to administer an extremely expensive drug to a Type 1 patient for which the disease is most certainly fatal and it’s something else to administer it to a Type 2 patient who could easily expect to live as long as I have or longer. Type 3 while it does leave them severely disabled could expect a normal life expectancy. Is it really worth it if there’s going to be no positive improvement or better outcomes?

In the video below a group of doctors discuss this new treatment as well as possible gene therapy treatments which are currently in phase 1 trials. They asked some of these tough questions about the advisability of using these treatments in adults for which improved outcomes are both unproven and in their opinion (and mine) unlikely.

They also asked a very disturbing yet appropriate question… If a Type 1 patient is not going to have a reasonable quality of life, should we use expensive and heroic measures to sustain that life or is it better to allow nature to take its course? These are very tough questions. I know people with Type 1 children and if I was in their shoes I could well appreciate their desire to do anything to keep their child alive. Still at some point, quality of life issues have to figure into the equation.

The bottom line is we still don’t know enough about how effective the new drug therapy is and we are a long way from knowing about the effectiveness and consequences of gene therapy treatments that are still in very early stage one trials.